The use of outcome data can serve as an important catalyst for improving career interventions. A follow-up to the Reese and Miller study was conducted over a 2-year period to assess whether modifications made to the course using the Reese and Miller data as a baseline resulted in subsequent improvements. Using a prepost group design that compared students in a career course designed for deciding students to a quasi-control group, data from modifications in the first year demonstrated a large increase in effect size (from 0.55 to 1.09) on a measure of career decision-making self-efficacy. The improvements in the course were maintained the second year (0.90). Uneven improvement, however, was found on a measure of perceived career difficulties from baseline. An overview of the modifications made to the course and the implications for incorporating outcome data in the provision of career services are discussed as are considerations for future research. (Contains 3 tables.)